1. Field of the Invention
The present general inventive concept relates to an inkjet printhead, and more particularly, to a thermal inkjet printhead having a chamber layer and a nozzle layer that are formed of improved materials and a method of manufacturing the inkjet printhead.
2. Description of the Related Art
Inkjet printheads are apparatuses for forming images by ejecting fine droplets of ink onto desired positions of a printing medium. Generally, there are two kinds inkjet printheads having different mechanisms for ejecting ink droplets. One is a thermal inkjet printhead that ejects the ink droplets using an expanding force of bubbles after bubbles have been generated in the ink using a thermal source, and the other one is a piezoelectric inkjet printhead that ejects the ink droplets using a pressure applied to the ink, which is caused by a deformation of a piezoelectric material.
The ink ejecting mechanism of the thermal inkjet printhead will be described in more detail as follows. When pulse current flows on a heater that is formed of a heating resistive element, the heater generates heat, and thus, the ink adjacent to the heater is heated instantly to a temperature of about 300° C. Accordingly, the ink boils and generates bubbles, and the generated bubbles expand to press ink filled in an ink chamber. Therefore, the ink around nozzles is ejected out of the ink chamber through the nozzles in the shape of droplets.
The thermal inkjet printhead includes a structure of sequentially stacked chamber and nozzle layers on a substrate, on which heaters are formed. The chamber layer includes a plurality of ink chambers, in which the ink to be ejected is filled, and the nozzle layer includes a plurality of nozzles ejecting the ink. According to the conventional art, the chamber layer is formed by stacking a dry film resist on the substrate and patterning the stacked dry film resist. In addition, the nozzle layer is formed by thermally compressing a plated nickel or polyimide on the chamber layer. Meanwhile, a technology of manufacturing the chamber layer and the nozzle layer through a single process by using a photosensitive epoxy has been developed recently.